Acetals of alkyl ethers of polyethylene glycols



Patented Sept. 29, 1931 UNITED STATES PATENT OFFICE JULIUS A. NIEUWLAND, OF NOTRE DAME, INDIANA, ASSIGNOR TOE. I. DU PONT DE NEMOURS & COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELA- W'ARE ACETAIJS F ALKYL ETHERS OF POLYETHY LEN E GLYCOLS No Drawing.

This invention relates to the preparation of acetals, and more particularly to the preparation of acetals from alcohols substituted with more than one ether group.

It is an object of this invention to produce a new class of compounds containing ether groups, these compounds having in general the following graphical formula:

CH CH (OCH CH OCH CH OR) 2,

ethyl group.

I have found that such compounds can be ether attached through the beta carbon of the produced by treating the corresponding alkyl alcohols with .acetylene in the presence of suitable catalysts, such as mercuric salts of anhydrous flue-acids.

A specific example illustrating the preparation of the acetal of the ethyl ether of diethylene glycol is as follows: a

A 20% solution of fluoboric acid in ethyl alcohol weighing 10 grams is warmed with two grams of mercuric oxide until a portion of the mercuric oxide has gone into solution. To this catalyst mixture is thenadded 200 grams of the ethyl ether of diethylene glycol, and acetylene is passed in until an increase in weight-of 20 grams occurs, corresponding to the absorption of one-half gram mole acetylene per gram mole of the ethyl ether of diethylene glycol. When the rate of the reaction decreases, additional mercuric oxide is added in two gram portions, not more than 10 to 12 grams being required for. a charge of this size. On the completion of the reaction the product isneutralized with saturated potassium carbonate solution, dried with anhydrouspotas'sium carbonate, and distilled yielding the acetal in a high state of purity.

The product is a Water white liquid with a boiling point of approximately to C.

under 14 mm. pressure, having the following structural'formula:

glycol, such as the methyl, propyl, butyl and.

ibenzyl'ethers, can be. prepared in a similar wily by adding acetylene in molecular propor- Applieatioir filed September 13, 1928. Serial No. 305,867. v

tions .to the corresponding ethers of diethylene glycol. The acetals of ethers of triethyleneglycol can also be prepared in the manner indicated, using the corresponding ethers of triethylene glycol.

The preparation of compounds of this class by the method indicated above is not limited to the. use of mercuric salts of fluoboric acid but mercuric salts of other acids, such as fluosilicic acid, may be used. Likewise, any of the standard methods for the preparation ofacetals can be used instead of the parti'cular method indicated above.

Acetals of the type set forth herein have been found to be excellent plasticizers for cellulose derivatives, but their use in that connection is not claimed herein as it forms the subject matter of copending application of Walter E. Lawson, Serial Number 305,873,

filed September 13, 1928, and allowed January As many apparently widely different embodiments of this invention may be made withoutdeparting from the spirit and scope thereof, it is to be understood that I'd0 not limit myself to' the specific embodiments thereof except as defined in the appended a patent claims.

-Iclaimf v 1'. Compounds having the following graphical formula:

OH GH OCH2CH2OCH2CH20R) 2,

where R. is an alkyl radical or an ethyl alkyl ether attached through the beta carbon of the ethyl group.

' 2. As a new compound, an acetal of an alkyl ether of a polyethylene glycol.

- 3. As a new compound, an acetal of an ethyl ether of a polyethylene glycol.

4. As a new compound, an acetal of an alkyl ether of'diethylene glycol.

5. As anew compound, the acetal ofthe ethyl ether ofdiethylene glycol.

6. A compound obtainable by the action of acetylene on an alkyl ether of diethylene glycol.

7 The method of reacting an alkyl alcohol containing more than one ether group with acetylene consisting in treating said alkyl alcohol with acetylene in the presence of a,

' catalyst consisting of a mercuric 'salt of a. fluo-a'cid."

8. The method of preparing the acetal of 5 the ethyl ether of diethylene glycol which consists inadding 200 parts by weight of the mixture until an increase of weight correethyl ether of diethylene glicol to a. catalyst made from 10 parts by Wei t of g1. 20% solution of fluoboric acid in etiyl alcohol which has been warmed with 2 parts by weight of mercuric oxide, in passing acetylene into this sponding to the absorption of one-half part by weight mole acetylene er part by welght mole of the ethyl ether 0 diethylene glycol has occurred, and in adding additional mercuric oxide when the rate of reaction decreases.

. In testimon whereoiI aflizi my si ature.- Y 

